Building a skyscraper-sized sea wall to protect lower Manhattan might sound a little far-fetched, but it’s a serious proposal coming from the former director of the Department of City Planning’s Manhattan office. “The thing we as a city have to understand is, we’ve been promoting all this waterfront development, and most of that waterfront development is happening in the zone that is getting evacuated right now,” said Vishaan Chakrabarti in a telephone interview with Observer.com. “We’re talking about thousands and thousands of housing units. It’s fine for that housing to be there, but we have to figure out a way to protect it all.”

Chakrabarti suggests there’s something we could learn from the Dutch, who built sea gates twice the size of the Eiffel Tower at the mouth of the Rhine to Rotterdam and its vital port from storm surges. Called Maeslantkering, or the “Maelstrom Barrier”, the gates can be closed when storms close in while still allowing ships to take shelter in the harbor. When the storm passes, the gates can be opened to allow for business as usual. It’s a clever idea but it comes with a big price tag. It cost the Dutch $4 billion to build the sea gate, and that was back in 1997. Since New York would probably need three different gates to fully protect waterfront developments, potential costs could be closer to $10 billion.

Still, New York is a city of investors, right? They should recognize a good venture when they see one. “Climate change is here, and we clearly have to acknowledge that these unusual weather events are going to become more and more frequent, and we’re going to have to do something about it because we could lose much more than we’re going to save if we don’t invest in the right infrastructure,” Mr. Chakrabarti said.